Adamantane is a stable, highly symmetrical compound in which four cyclohexane rings are condensed to form a cage-like structure. It is known that adamantane derivatives, which show peculiar functions, are useful as raw materials for medical materials and highly functional industrial materials. Further, because an adamantane compound has specific optical characteristics and heat resistance, an attempt has been made to use it as, for example, an optical disc substrate, an optical fiber or a lens (see, for example, Patent Documents 1 and 2). Further, an attempt has been made to use an adamantane ester as a raw material resin for a photoresist by utilizing its acid-sensitive property, dry etching resistance and transparency to UV light (see, for example, Patent Document 3).
In recent years, studies have been progressing for high precision, wider viewing angle and enhanced image quality of a flat panel display using a liquid crystal, an organic electroluminescence (EL) device and the like, for higher intensity, shorter wavelength and whitening of a light source using a light emitting diode (optical semiconductor) such as LED and the like, for higher frequency of an electronic circuit and for higher performance and improvement of an optical or electronic component such as an optical circuit or communication.
As a method for such an improvement, there have been investigated and developed basic materials such as a liquid crystal material and a light emitting material for an organic EL device. Investigation has also been made to seek higher performance of a resin that is used along with those basic materials as a coating material, a sealant or an adhesive. As a resin used for a coating material, a sealant or an adhesive of an optical or electronic component, various kinds of thermosetting resins, light-curable resins and thermoplastic resins have been applied. Such resins have been used in accordance with their respective characteristics by themselves such as heat resistance, transparency, solubility and adhesiveness.
In the field of LED which is advanced in terms of high performance, an illumination and a light using a white LED composed of a near ultra violet or blue light emitting device have been proposed and developed for practical use. In addition, it is expected that they will be developed to be used for home lighting and automobiles in the future. In an LED device, an inorganic semiconductor is sealed with a resin containing a fluorescent material. In this case, a conventional thermosetting resin such as a bisphenol A epoxy resin has limitation in heat resistance and light resistance. Thus there is a demand for a sealant which can fulfill the required characteristics (see, for example, Non-Patent Document 1).
Further, in the display field, an organic EL device of small size, high precision and energy saving is used. Also employed is an organic EL device of a top emission type. Accordingly, a sealing resin for use in an organic EL device is required not only to have a function of bonding a conventional sealing board such as stainless steel to a glass substrate and a function as a gas barrier, but also to exhibit, by itself, transparency, light resistance, heat resistance, mechanical strength, etc. (see, for example, Non-Patent Document 2).
Further, in the field of an electronic circuit integrated with a semiconductor, etc., an increase in volume of information and in communication speed and miniaturization of a device have been developed with the progress of an information-oriented society. Thus, further miniaturization, integration and increase of frequency are demanded. Furthermore, an optical circuit using an optical wave guide, etc. that enables higher speed processing has also been investigated. When a customarily employed resin such as a bisphenol A epoxy resin is used as a sealing resin or a resin for a film or a lens for the above circuits, the following problems are caused. Namely, in the case of an electronic circuit, the dielectric constant increases and heat resistance becomes insufficient. In the case of the optical wave guide and LED sealing, a reduction of transparency and yellow coloring of the resin by deterioration thereof due to light absorption by aromatic rings are caused.
Further, when a customarily employed resin such as a bisphenol A epoxy resin is used as an electric or electronic material, and when a cured product thereof has a high chlorine content, chlorine ions are formed by hydrolysis in moistened conditions. Because chlorine ions cause a reduction of electric insulation and a corrosion of the electric circuit, there is a demand for a low chlorine content epoxy resin.
On the other hand, a polymer compound having an adamantane skeleton is excellent in heat resistance. A polyester and a polycarbonate using an adamantane diol, for example, are known as such polymer compounds. Also, as a resin composition using an adamantane, there are disclosed a resin composition containing 1,3-bis(glycidyloxyphenyl) adamantane (see, for example, Patent Document 4) and a resin composition containing 2,2-bis(glycidyloxyphenyl)adamantane (see, for example, Patent Document 5). Although these resin compositions show a lowered dielectric constant and an improved transparency as compared with a bisphenol A epoxy resin, there are caused problems that these resins, which are crystalline compounds with high melting points, have poor compatibility with other epoxy resins and poor solubility in solvents and, therefore, have poor workability and cannot be used in an amount required to obtain a desired performance.    [Patent Document 1] Japanese Unexamined Patent Application Publication No. H06-305044    [Patent Document 2] Japanese Unexamined Patent Application Publication No. H09-302077    [Patent Document 3] Japanese Unexamined Patent Application Publication No. H04-39665    [Non-Patent Document 1] Monthly “Material Stage,” June 2003, pages 20 to 24    [Non-Patent Document 2] Monthly “Material Stage,” March 2003, pages 52 to 64    [Patent Document 4] Japanese Unexamined Patent Application Publication No. 2003-321530    [Patent Document 5] Japanese Unexamined Patent Application Publication No. H10-130371